How bad could spam become?
There are around 22 million small businesses in the United States alone. Assume that spam became an accepted form of advertising. Assume that just one percent of those businesses decided to advertise with spam. Assume that the one percent only sent one spam message per year. How many does that work out to in your personal mailbox (which you bought and paid for, with your own money, for your purposes)? Around six hundred unwanted e-mails in your mailbox, each and every day of the year. Around six hundred off-topic messages in every newsgroup you read, every day. At that rate, the messages you want to see, the news you want to read, the discussions you want to participate in, the letters you want to get, will be squeezed out.